The present invention relates to a method and apparatus for displaying, on an image display unit, picture frames of color photographic films taken with a television camera. More particularly, the present invention relates to a method and apparatus for displaying picture frames of various sizes at the same dimension on an image display unit, by thinning pixels based on the size of a frame, and writing the thinned image data in an image memory.
A video type color film analyzer estimates the quality of a color image within a picture frame of a color photographic film using an image display system, prior to printing it out. Each picture frame of a color photographic film is taken with a television (TV) camera and the pixel image data are stored in an image memory. The image data read out from the image memory are processed and therefore are displayed on an image display unit, such as a color CRT, in the form of a color positive image. An operator checks the image displayed on the color CRT to see whether a finished print thereof would be acceptable. If not, the operator empirically determines exposure correction data according to which the exposure light amount is set and the picture frame is printed.
According to known picture frame display arrangements, a plurality of color CRTs are arranged in a line to display one color picture image per one color CRT as disclosed, e.g., in Japanese Patent Laid Open Publication No. 62-141530, or a plurality of color picture images are displayed in a matrix pattern on one color CRT as disclosed, e.g., in European Unexamined Patent Publication No. 0108158.
The TV camera of the above-mentioned known color film analyzer has its optical magnification factor adjusted such that a full-size color picture image of a 135 type photographic film (35 mm photographic film within a patrone) is displayed on the whole effective display or image pickup area. Such a fixed magnification factor has been used because most amateurs use 135 type photographic films (hereinafter simply called "135 F"). As a result, if a 135 type half size color photographic film (hereinafter simply called "135 H") or a 110 type color photographic film (hereinafter simply called "110 type"), both having a frame size smaller than that of "135 F" is used, the image of a color picture frame is displayed at a reduced size on the color CRT, resulting in a difficulty of inspecting a color image, inefficient use of the image memory, and reduced effective display area of the color CRT.
Adjusting an image size (changing a magnification) generally is performed by means of an optical system such as a zoom lens. Such an optical magnification change necessitates the use of a zoom lens, a pulse motor, a lens position detector and the like, resulting in poor cost effectiveness in spite of size standardization of color photographic films and a small number of types.